CHICAGO — Members of the Asian Carp Regional Coordinating Committee (ACRCC) released March 15 the first interim report of the Asian Carp Environmental DNA Calibration Study (ECALS).

The U.S. Army Corps of Engineers is leading this two-year study in conjunction with the U.S. Geological Survey and the U.S. Fish and Wildlife Service to reduce the uncertainty surrounding Asian carp environmental DNA (eDNA) results.

eDNA is a process in which genetic material (cells containing DNA from mucus, feces and/or urine) is extracted from water samples to detect the possible presence of Asian carp.

A new ECALS page on the ACRCC’s website Asiancarp.us will host interim reports and tentative release dates for upcoming interim reports and document the progress of the study.

“At present, eDNA evidence cannot verify whether live Asian carp are present, whether the DNA may have come from a dead fish, or whether water containing Asian carp DNA may have been transported from other sources such as bilge water, storm sewers or fish-eating birds,” said Kelly Baerwaldt, ACRCC eDNA program manager.

ECALS will investigate alternative sources and pathways for eDNA detections beyond a live fish. The study will also examine how environmental variables such as light, temperature and water velocity impact eDNA detections; explore the correlation between the number of positive samples and the strength of the DNA source; develop more efficient eDNA markers to cut the sampling processing time in half and model eDNA transport specific to the Chicago Area Waterway System.

This first interim report provides results to date from the study, including storm sewer experiments, fertilization analysis and alternative sampling trials to make the sampling process more efficient. For example, an initial trial on Chinatown storm sewers demonstrates that ice contaminated with Asian carp DNA and deposited into storm drains may serve as a source of eDNA and testing on two brands of fertilizer, as Asian carp are used as ingredients in some, failed to detect bighead or silver carp DNA. Moreover, the differences in sampling at different depths were investigated, and it was found that surface sampling was the most successful in detecting eDNA.